to declare (oneself) aloof from association or union with somebody or something else
I dissociate myself from my colleague's remarks
to separate (two ideas) in the mind
It's difficult to dissociate him from his television persona
to subject (a compound) to chemical dissociation
said of a chemical compound: to undergo dissociation
dissociative /-i·ətiv/ adj
[Latin dissociatus, past part. of dissociare, from dis- + sociare to join, from socius companion]